1. Field of the Invention
The present invention relates to drive arrangements for roller conveyors and, more particularly, to such an arrangement wherein rotary power is taken by a single belt from a longitudinal shaft and transmitted through a clutch to a roller drive belt engaged with the rollers.
2. Description of the Prior Art
Arrangements for propelling the rollers on roller conveyors include the type wherein the rollers are engaged and driven by long endless belts, each belt being driven by a motor. In another type a long drive shaft extending longitudinally of the conveyor is connected to individual rollers by endless belts twisted 90.degree. and drivingly engaging the drive shaft and the rollers.
Problems associated with the longitudinal drive shaft type of arrangement result from the drive shaft being long and heavy and generally not easily disassembled. Further, the belts or O-rings are endless, whereby replacement is laborious because of the necessity of disconnecting the shaft to slip new belts thereon and of disengaging the belts from the rollers and sliding them along the shaft to fill in the positions of the broken or worn belts.
One solution to this problem is to employ the plurality of shorter shafts which are selectively driven by frictional or geared connection to the main shaft, the shorter shafts each being connected by endless belts to the individual rollers. By this means belt replacement is simplified somewhat. The use of the shorter shafts is further convenient for use on accumulation conveyors with the rollers in each accumulation zone driven by the same short shaft. However, the coupling of each roller to a shaft with an individual belt results in a significant quantity of belts which must be employed and maintained.